Objective To investigate the minimum local analgesic concentration(MLAC)of epidural hydromorphone combined with bupivacaine for analgesia during the first stage of labor by establishing clinical model.Methods Sixty four labouring parturi-ents at 3-7 cm cervical dilation who requested epidural analgesia were allocated to one of two groups.After a lumbar epidural cath-eter was placed,study participants received 15 mL bupivacaine(n=30),bupivacaine with hydromorphone 200 μg(n=30).The con-centration of bupivacaine was determined by the response of the previous patient using 0 - 100 mm visual analog pain scores, with≤30 mm within 30 min defined as effective.Results Four women were excluded,leaving 30 patients in each of the two groups for analysis.The MLAC of bupivacaine alone was 0.103%(95% CI :0.094%-0.113%).The addition of hydromorphone at doses of 200 μg resulted in significant reduction(P <0.05)in the MLAC of bupivacaine to 0.044%(95% CI :0.034%-0.053%),the difference was significant (P <0.05).There was no significant difference in Bromage scores,HR,BP,FHR,UC and adverse reac-tion (P >0.05).Conclusion The study showed a significant reduction in the MLAC of bupivacaine by hydromorphone.Hydromor-phone could be safely used in epidural analgesia for labor.

Objective To evaluate the effects of exendin-4 on glial brillary acidic protein (GFAP ) and interleukin-1β(IL-1β) expression in hippocampi of aged rats .Methods Forty-eight healthy male Sprague-Dawley rats ,aged 22-24 weeks ,weighing 500-700 g ,were randomly divided into 4 groups (n=12 each) using a random number table:control group (group C ) ,exendin-4 group (group E ) ,operation group (group O ) and exendin-4 plus operation group (group OE) .The rats were anesthetized with intraperitoneal fentanyl and droperidol .Groups C and E did not receive anesthesia or splenectomy .In O and OE groups ,splenectomy was carried out .In E and OE groups , exendin-4 5 μg/kg was injected intraperitoneally at 30 min before skin incision and 12 h after operation .C and O groups received the equal volume of normal saline instead of exendin-4 .Learning and memory function was assessed using Morris water maze test (escape latency (EL) and total swimming distance (TSD) at 1 day before operation (T0 ) .The fasting blood glucose was measured after anesthesia (T1 ) ,at the end of operation (T2 ) and on postoperative day 1 (T3 ) .The rats were sacrificed after assessment of the cognitive function at T 3 and the hippocampi were removed for determination of the expression of GFAP (by immuno-histochemistry ) and IL-1β(by Western blot ) .Results There was no significant difference in the EL and TSD at T0 between the four groups ( P>0.05) .Compared with group C ,the EL and TSD were significantly prolonged at T3 and fasting blood glucose was increased at T2 ,3 ,and the expression of IL-1βand GFAP was up-regulated at T3 in O and OE groups ( P<0.05) .Compared with group O ,the EL and TSD were significantly prolonged at T3 and fasting blood glucose was decreased at T2 ,3 ,and the expression of IL-1βand GFAP was down-regulated at T3 in group OE ( P<0.05) . Conclusion Exendin-4 can improve the postoperative cognitive function of aged rats by inhibiting inflammatory responses in hippocampi and maintaining stable perioperative blood glucose .